From 64b8c083f9685b15b9c9eb9af787f679daad012c Mon Sep 17 00:00:00 2001 From: Zach van Rijn Date: Sat, 30 Apr 2022 01:00:37 -0500 Subject: scripts/*: add dependency resolver. --- scripts/tsort.c | 491 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 491 insertions(+) create mode 100644 scripts/tsort.c (limited to 'scripts/tsort.c') diff --git a/scripts/tsort.c b/scripts/tsort.c new file mode 100644 index 000000000..e307268da --- /dev/null +++ b/scripts/tsort.c @@ -0,0 +1,491 @@ +/*- + * SPDX-License-Identifier: BSD-3-Clause + * + * Copyright (c) 1989, 1993, 1994 + * The Regents of the University of California. All rights reserved. + * + * This code is derived from software contributed to Berkeley by + * Michael Rendell of Memorial University of Newfoundland. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#ifndef lint +static const char copyright[] = +"@(#) Copyright (c) 1989, 1993, 1994\n\ + The Regents of the University of California. All rights reserved.\n"; +#endif /* not lint */ + +#ifndef lint +static const char sccsid[] = "@(#)tsort.c 8.3 (Berkeley) 5/4/95"; +#endif /* not lint */ + +#include + +#include + +#include +#include +#include +#include +#include +#include +#include +#include + +/* + * Topological sort. Input is a list of pairs of strings separated by + * white space (spaces, tabs, and/or newlines); strings are written to + * standard output in sorted order, one per line. + * + * usage: + * tsort [-dlq] [inputfile] + * If no input file is specified, standard input is read. + * + * Should be compatible with AT&T tsort HOWEVER the output is not identical + * (i.e. for most graphs there is more than one sorted order, and this tsort + * usually generates a different one then the AT&T tsort). Also, cycle + * reporting seems to be more accurate in this version (the AT&T tsort + * sometimes says a node is in a cycle when it isn't). + * + * Michael Rendell, michael@stretch.cs.mun.ca - Feb 26, '90 + */ + +#define NF_MARK 0x1 /* marker for cycle detection */ +#define NF_ACYCLIC 0x2 /* this node is cycle free */ +#define NF_NODEST 0x4 /* Unreachable */ + + +typedef struct node_str NODE; + +struct node_str { + NODE **n_prevp; /* pointer to previous node's n_next */ + NODE *n_next; /* next node in graph */ + NODE **n_arcs; /* array of arcs to other nodes */ + int n_narcs; /* number of arcs in n_arcs[] */ + int n_arcsize; /* size of n_arcs[] array */ + int n_refcnt; /* # of arcs pointing to this node */ + int n_flags; /* NF_* */ + char n_name[1]; /* name of this node */ +}; + +typedef struct _buf { + char *b_buf; + int b_bsize; +} BUF; + +#define HASH_CHUNK_SIZE 64 +#define HASH_BUCKET_COUNT 1024 + +struct hash_elem { + NODE *elem; + struct hash_elem *next; +}; + +struct hash_chunk { + struct hash_elem elems[HASH_CHUNK_SIZE]; + struct hash_chunk *next; +}; + +struct hash { + struct hash_elem **elems; + struct hash_chunk *chunks; + struct hash_elem *top; +}; + +static void hash_init(struct hash *h) { + h->chunks = NULL; + h->top = NULL; + h->elems = calloc(1024, sizeof(struct hash_elem *)); +} + +static void hash_destroy(struct hash *h) { + for (size_t i = 0; i < HASH_BUCKET_COUNT; ++i) { + struct hash_elem *e = h->elems[i]; + while (e) { + free(e->elem->n_arcs); + free(e->elem); + e = e->next; + } + } + free(h->elems); + while (h->chunks) { + struct hash_chunk *c = h->chunks; + h->chunks = h->chunks->next; + free(c); + } +} + +static size_t hash_key(char *key) { + size_t h = 5381; + for (size_t i = 0, k; (k = key[i]); ++i) + h = ((h << 5) + h) ^ k; + return h; +} + +static NODE *hash_find(struct hash *h, char *key) { + size_t hash = hash_key(key) & (HASH_BUCKET_COUNT - 1); + for (struct hash_elem *c = h->elems[hash]; c; c = c->next) { + if (!strcmp(key, c->elem->n_name)) + return c->elem; + } + return NULL; +} + +static struct hash_elem *hash_insert(struct hash *h, char *key) { + size_t hash = hash_key(key) & (HASH_BUCKET_COUNT - 1); + if (!h->top) { + struct hash_chunk *c = calloc(1, sizeof(struct hash_chunk)); + c->next = h->chunks; + h->chunks = c; + for (size_t i = 0; i < (HASH_CHUNK_SIZE - 1); ++i) + c->elems[i].next = &c->elems[i + 1]; + c->elems[HASH_CHUNK_SIZE - 1].next = h->top; + h->top = c->elems; + } + struct hash_elem *hc = h->top; + h->top = h->top->next; + hc->next = h->elems[hash]; + h->elems[hash] = hc; + return hc; +} + +static struct hash db; +static NODE *graph, **cycle_buf, **longest_cycle; +static int debug, longest, quiet; + +static void add_arc(char *, char *); +static int find_cycle(NODE *, NODE *, int, int); +static NODE *get_node(char *); +static void *grow_buf(void *, size_t); +static void remove_node(NODE *); +static void clear_cycle(void); +static void tsort(void); +static void usage(void); + +int +main(int argc, char *argv[]) +{ + BUF *b; + int c, n; + FILE *fp; + int bsize, ch, nused; + BUF bufs[2]; + + fp = NULL; + while ((ch = getopt(argc, argv, "dlq")) != -1) + switch (ch) { + case 'd': + debug = 1; + break; + case 'l': + longest = 1; + break; + case 'q': + quiet = 1; + break; + case '?': + default: + usage(); + } + argc -= optind; + argv += optind; + + switch (argc) { + case 0: + fp = stdin; + break; + case 1: + if ((fp = fopen(*argv, "r")) == NULL) + err(1, "%s", *argv); + break; + default: + usage(); + } + + for (b = bufs, n = 2; --n >= 0; b++) + b->b_buf = grow_buf(NULL, b->b_bsize = 1024); + + hash_init(&db); + + /* parse input and build the graph */ + for (n = 0, c = getc(fp);;) { + while (c != EOF && isspace(c)) + c = getc(fp); + if (c == EOF) + break; + + nused = 0; + b = &bufs[n]; + bsize = b->b_bsize; + do { + b->b_buf[nused++] = c; + if (nused == bsize) + b->b_buf = grow_buf(b->b_buf, bsize *= 2); + c = getc(fp); + } while (c != EOF && !isspace(c)); + + b->b_buf[nused] = '\0'; + b->b_bsize = bsize; + if (n) + add_arc(bufs[0].b_buf, bufs[1].b_buf); + n = !n; + } + (void)fclose(fp); + if (n) + errx(1, "odd data count"); + + /* do the sort */ + tsort(); + hash_destroy(&db); + exit(0); +} + +/* double the size of oldbuf and return a pointer to the new buffer. */ +static void * +grow_buf(void *bp, size_t size) +{ + if ((bp = realloc(bp, size)) == NULL) + err(1, NULL); + return (bp); +} + +/* + * add an arc from node s1 to node s2 in the graph. If s1 or s2 are not in + * the graph, then add them. + */ +static void +add_arc(char *s1, char *s2) +{ + NODE *n1; + NODE *n2; + int bsize, i; + + n1 = get_node(s1); + + if (!strcmp(s1, s2)) + return; + + n2 = get_node(s2); + + /* + * Check if this arc is already here. + */ + for (i = 0; i < n1->n_narcs; i++) + if (n1->n_arcs[i] == n2) + return; + /* + * Add it. + */ + if (n1->n_narcs == n1->n_arcsize) { + if (!n1->n_arcsize) + n1->n_arcsize = 10; + bsize = n1->n_arcsize * sizeof(*n1->n_arcs) * 2; + n1->n_arcs = grow_buf(n1->n_arcs, bsize); + n1->n_arcsize = bsize / sizeof(*n1->n_arcs); + } + n1->n_arcs[n1->n_narcs++] = n2; + ++n2->n_refcnt; +} + +/* Find a node in the graph (insert if not found) and return a pointer to it. */ +static NODE * +get_node(char *name) +{ + NODE *n = hash_find(&db, name); + size_t nlen; + + if (n) + return n; + + nlen = strlen(name) + 1; + + if ((n = malloc(sizeof(NODE) + nlen)) == NULL) + err(1, NULL); + + n->n_narcs = 0; + n->n_arcsize = 0; + n->n_arcs = NULL; + n->n_refcnt = 0; + n->n_flags = 0; + bcopy(name, n->n_name, nlen); + + /* Add to linked list. */ + if ((n->n_next = graph) != NULL) + graph->n_prevp = &n->n_next; + n->n_prevp = &graph; + graph = n; + + /* Add to hash table. */ + hash_insert(&db, name)->elem = n; + return (n); +} + + +/* + * Clear the NODEST flag from all nodes. + */ +static void +clear_cycle(void) +{ + NODE *n; + + for (n = graph; n != NULL; n = n->n_next) + n->n_flags &= ~NF_NODEST; +} + +/* do topological sort on graph */ +static void +tsort(void) +{ + NODE *n, *next; + int cnt, i; + + while (graph != NULL) { + /* + * Keep getting rid of simple cases until there are none left, + * if there are any nodes still in the graph, then there is + * a cycle in it. + */ + do { + for (cnt = 0, n = graph; n != NULL; n = next) { + next = n->n_next; + if (n->n_refcnt == 0) { + remove_node(n); + ++cnt; + } + } + } while (graph != NULL && cnt); + + if (graph == NULL) + break; + + if (!cycle_buf) { + /* + * Allocate space for two cycle logs - one to be used + * as scratch space, the other to save the longest + * cycle. + */ + for (cnt = 0, n = graph; n != NULL; n = n->n_next) + ++cnt; + cycle_buf = malloc(sizeof(NODE *) * cnt); + longest_cycle = malloc(sizeof(NODE *) * cnt); + if (cycle_buf == NULL || longest_cycle == NULL) + err(1, NULL); + } + for (n = graph; n != NULL; n = n->n_next) + if (!(n->n_flags & NF_ACYCLIC)) { + if ((cnt = find_cycle(n, n, 0, 0))) { + if (!quiet) { + warnx("cycle in data"); + for (i = 0; i < cnt; i++) + warnx("%s", + longest_cycle[i]->n_name); + } + remove_node(n); + clear_cycle(); + break; + } else { + /* to avoid further checks */ + n->n_flags |= NF_ACYCLIC; + clear_cycle(); + } + } + + if (n == NULL) + errx(1, "internal error -- could not find cycle"); + } +} + +/* print node and remove from graph (does not actually free node) */ +static void +remove_node(NODE *n) +{ + NODE **np; + int i; + + (void)printf("%s\n", n->n_name); + for (np = n->n_arcs, i = n->n_narcs; --i >= 0; np++) + --(*np)->n_refcnt; + n->n_narcs = 0; + *n->n_prevp = n->n_next; + if (n->n_next) + n->n_next->n_prevp = n->n_prevp; +} + + +/* look for the longest? cycle from node from to node to. */ +static int +find_cycle(NODE *from, NODE *to, int longest_len, int depth) +{ + NODE **np; + int i, len; + + /* + * avoid infinite loops and ignore portions of the graph known + * to be acyclic + */ + if (from->n_flags & (NF_NODEST|NF_MARK|NF_ACYCLIC)) + return (0); + from->n_flags |= NF_MARK; + + for (np = from->n_arcs, i = from->n_narcs; --i >= 0; np++) { + cycle_buf[depth] = *np; + if (*np == to) { + if (depth + 1 > longest_len) { + longest_len = depth + 1; + (void)memcpy((char *)longest_cycle, + (char *)cycle_buf, + longest_len * sizeof(NODE *)); + } + } else { + if ((*np)->n_flags & (NF_MARK|NF_ACYCLIC|NF_NODEST)) + continue; + len = find_cycle(*np, to, longest_len, depth + 1); + + if (debug) + (void)printf("%*s %s->%s %d\n", depth, "", + from->n_name, to->n_name, len); + + if (len == 0) + (*np)->n_flags |= NF_NODEST; + + if (len > longest_len) + longest_len = len; + + if (len > 0 && !longest) + break; + } + } + from->n_flags &= ~NF_MARK; + return (longest_len); +} + +static void +usage(void) +{ + (void)fprintf(stderr, "usage: tsort [-dlq] [file]\n"); + exit(1); +} -- cgit v1.2.3-70-g09d2